diff --git a/ICSharpCode.NRefactory/Editor/IDocument.cs b/ICSharpCode.NRefactory/Editor/IDocument.cs
index 4201ce4484..f9a793b911 100644
--- a/ICSharpCode.NRefactory/Editor/IDocument.cs
+++ b/ICSharpCode.NRefactory/Editor/IDocument.cs
@@ -109,6 +109,18 @@ namespace ICSharpCode.NRefactory.Editor
 		/// </remarks>
 		void Insert(int offset, string text);
 		
+		/// <summary>
+		/// Inserts text.
+		/// </summary>
+		/// <param name="offset">The offset at which the text is inserted.</param>
+		/// <param name="text">The new text.</param>
+		/// <remarks>
+		/// Anchors positioned exactly at the insertion offset will move according to their movement type.
+		/// For AnchorMovementType.Default, they will move behind the inserted text.
+		/// The caret will also move behind the inserted text.
+		/// </remarks>
+		void Insert(int offset, ITextSource text);
+		
 		/// <summary>
 		/// Inserts text.
 		/// </summary>
@@ -121,6 +133,18 @@ namespace ICSharpCode.NRefactory.Editor
 		/// </param>
 		void Insert(int offset, string text, AnchorMovementType defaultAnchorMovementType);
 		
+		/// <summary>
+		/// Inserts text.
+		/// </summary>
+		/// <param name="offset">The offset at which the text is inserted.</param>
+		/// <param name="text">The new text.</param>
+		/// <param name="defaultAnchorMovementType">
+		/// Anchors positioned exactly at the insertion offset will move according to the anchor's movement type.
+		/// For AnchorMovementType.Default, they will move according to the movement type specified by this parameter.
+		/// The caret will also move according to the <paramref name="defaultAnchorMovementType"/> parameter.
+		/// </param>
+		void Insert(int offset, ITextSource text, AnchorMovementType defaultAnchorMovementType);
+		
 		/// <summary>
 		/// Removes text.
 		/// </summary>
@@ -136,6 +160,14 @@ namespace ICSharpCode.NRefactory.Editor
 		/// <param name="newText">The new text.</param>
 		void Replace(int offset, int length, string newText);
 		
+		/// <summary>
+		/// Replaces text.
+		/// </summary>
+		/// <param name="offset">The starting offset of the text to be replaced.</param>
+		/// <param name="length">The length of the text to be replaced.</param>
+		/// <param name="newText">The new text.</param>
+		void Replace(int offset, int length, ITextSource newText);
+		
 		/// <summary>
 		/// Make the document combine the following actions into a single
 		/// action for undo purposes.
diff --git a/ICSharpCode.NRefactory/Editor/ReadOnlyDocument.cs b/ICSharpCode.NRefactory/Editor/ReadOnlyDocument.cs
index a4d76a8394..2a36ccda33 100644
--- a/ICSharpCode.NRefactory/Editor/ReadOnlyDocument.cs
+++ b/ICSharpCode.NRefactory/Editor/ReadOnlyDocument.cs
@@ -257,6 +257,21 @@ namespace ICSharpCode.NRefactory.Editor
 			throw new NotSupportedException();
 		}
 		
+		void IDocument.Insert(int offset, ITextSource text)
+		{
+			throw new NotImplementedException();
+		}
+		
+		void IDocument.Insert(int offset, ITextSource text, AnchorMovementType defaultAnchorMovementType)
+		{
+			throw new NotImplementedException();
+		}
+		
+		void IDocument.Replace(int offset, int length, ITextSource newText)
+		{
+			throw new NotImplementedException();
+		}
+		
 		void IDocument.StartUndoableAction()
 		{
 		}
diff --git a/ICSharpCode.NRefactory/Editor/StringBuilderDocument.cs b/ICSharpCode.NRefactory/Editor/StringBuilderDocument.cs
index 79553a4136..f69070a196 100644
--- a/ICSharpCode.NRefactory/Editor/StringBuilderDocument.cs
+++ b/ICSharpCode.NRefactory/Editor/StringBuilderDocument.cs
@@ -104,17 +104,35 @@ namespace ICSharpCode.NRefactory.Editor
 			Replace(offset, 0, text);
 		}
 		
+		/// <inheritdoc/>
+		public void Insert(int offset, ITextSource text)
+		{
+			if (text == null)
+				throw new ArgumentNullException("text");
+			Replace(offset, 0, text.Text);
+		}
+		
 		/// <inheritdoc/>
 		public void Insert(int offset, string text, AnchorMovementType defaultAnchorMovementType)
 		{
 			if (offset < 0 || offset > this.TextLength)
 				throw new ArgumentOutOfRangeException("offset");
+			if (text == null)
+				throw new ArgumentNullException("text");
 			if (defaultAnchorMovementType == AnchorMovementType.BeforeInsertion)
 				PerformChange(new InsertionWithMovementBefore(offset, text));
 			else
 				Replace(offset, 0, text);
 		}
 		
+		/// <inheritdoc/>
+		public void Insert(int offset, ITextSource text, AnchorMovementType defaultAnchorMovementType)
+		{
+			if (text == null)
+				throw new ArgumentNullException("text");
+			Insert(offset, text.Text, defaultAnchorMovementType);
+		}
+		
 		[Serializable]
 		sealed class InsertionWithMovementBefore : TextChangeEventArgs
 		{
@@ -149,6 +167,14 @@ namespace ICSharpCode.NRefactory.Editor
 			PerformChange(new TextChangeEventArgs(offset, b.ToString(offset, length), newText));
 		}
 		
+		/// <inheritdoc/>
+		public void Replace(int offset, int length, ITextSource newText)
+		{
+			if (newText == null)
+				throw new ArgumentNullException("newText");
+			Replace(offset, length, newText.Text);
+		}
+		
 		bool isInChange;
 		
 		void PerformChange(TextChangeEventArgs change)
@@ -166,7 +192,7 @@ namespace ICSharpCode.NRefactory.Editor
 					documentSnapshot = null;
 					cachedText = null;
 					b.Remove(change.Offset, change.RemovalLength);
-					b.Insert(change.Offset, change.InsertedText);
+					b.Insert(change.Offset, change.InsertedText.Text);
 					versionProvider.AppendChange(change);
 					
 					// Update anchors and fire Deleted events
diff --git a/ICSharpCode.NRefactory/Editor/StringTextSource.cs b/ICSharpCode.NRefactory/Editor/StringTextSource.cs
index 3a24db3646..36780954bd 100644
--- a/ICSharpCode.NRefactory/Editor/StringTextSource.cs
+++ b/ICSharpCode.NRefactory/Editor/StringTextSource.cs
@@ -27,6 +27,11 @@ namespace ICSharpCode.NRefactory.Editor
 	[Serializable]
 	public class StringTextSource : ITextSource
 	{
+		/// <summary>
+		/// Gets a text source containing the empty string.
+		/// </summary>
+		public static readonly StringTextSource Empty = new StringTextSource(string.Empty);
+		
 		readonly string text;
 		readonly ITextSourceVersion version;
 		
@@ -69,7 +74,7 @@ namespace ICSharpCode.NRefactory.Editor
 		/// <inheritdoc/>
 		public ITextSource CreateSnapshot()
 		{
-			return this; // StringTextBuffer is immutable
+			return this; // StringTextSource is immutable
 		}
 		
 		/// <inheritdoc/>
diff --git a/ICSharpCode.NRefactory/Editor/TextChangeEventArgs.cs b/ICSharpCode.NRefactory/Editor/TextChangeEventArgs.cs
index 936de37aa4..f1eeb4d27f 100644
--- a/ICSharpCode.NRefactory/Editor/TextChangeEventArgs.cs
+++ b/ICSharpCode.NRefactory/Editor/TextChangeEventArgs.cs
@@ -28,8 +28,8 @@ namespace ICSharpCode.NRefactory.Editor
 	public class TextChangeEventArgs : EventArgs
 	{
 		readonly int offset;
-		readonly string removedText;
-		readonly string insertedText;
+		readonly ITextSource removedText;
+		readonly ITextSource insertedText;
 		
 		/// <summary>
 		/// The offset at which the change occurs.
@@ -41,7 +41,7 @@ namespace ICSharpCode.NRefactory.Editor
 		/// <summary>
 		/// The text that was removed.
 		/// </summary>
-		public string RemovedText {
+		public ITextSource RemovedText {
 			get { return removedText; }
 		}
 		
@@ -49,13 +49,13 @@ namespace ICSharpCode.NRefactory.Editor
 		/// The number of characters removed.
 		/// </summary>
 		public int RemovalLength {
-			get { return removedText.Length; }
+			get { return removedText.TextLength; }
 		}
 		
 		/// <summary>
 		/// The text that was inserted.
 		/// </summary>
-		public string InsertedText {
+		public ITextSource InsertedText {
 			get { return insertedText; }
 		}
 		
@@ -63,7 +63,7 @@ namespace ICSharpCode.NRefactory.Editor
 		/// The number of characters inserted.
 		/// </summary>
 		public int InsertionLength {
-			get { return insertedText.Length; }
+			get { return insertedText.TextLength; }
 		}
 		
 		/// <summary>
@@ -71,9 +71,23 @@ namespace ICSharpCode.NRefactory.Editor
 		/// </summary>
 		public TextChangeEventArgs(int offset, string removedText, string insertedText)
 		{
+			if (offset < 0)
+				throw new ArgumentOutOfRangeException("offset", offset, "offset must not be negative");
 			this.offset = offset;
-			this.removedText = removedText ?? string.Empty;
-			this.insertedText = insertedText ?? string.Empty;
+			this.removedText = removedText != null ? new StringTextSource(removedText) : StringTextSource.Empty;
+			this.insertedText = insertedText != null ? new StringTextSource(insertedText) : StringTextSource.Empty;
+		}
+		
+		/// <summary>
+		/// Creates a new TextChangeEventArgs object.
+		/// </summary>
+		public TextChangeEventArgs(int offset, ITextSource removedText, ITextSource insertedText)
+		{
+			if (offset < 0)
+				throw new ArgumentOutOfRangeException("offset", offset, "offset must not be negative");
+			this.offset = offset;
+			this.removedText = removedText ?? StringTextSource.Empty;
+			this.insertedText = insertedText ?? StringTextSource.Empty;
 		}
 		
 		/// <summary>